“the language of the Kingdom”

The disciples of Christ taught His Faith with the language of the Kingdom. That language conformeth to all languages, for it consisteth of celestial meanings and divine mysteries. For the one who becometh conversant with that language the realities and secrets of creation stand unveiled before him. Divine truths are common to all languages. The Holy Spirit, therefore, taught the disciples the language of the Kingdom, and they thus were able to converse with the people of all nations. Whenever they spoke to those of other nations of the world, it was as if they conversed in their tongues. The well-known and outstanding languages of the world number about a thousand. It was necessary for the disciples to have written the Gospels in at least one of the languages of other nations. Thus, as it is known, the Gospels were written only in Hebrew and Greek, and not even in the language of the Romans, although it was at the time the official language. As the disciples were not well-versed in it, the Gospels were not written in that language. 

- ‘Abdu’l-Baha  (From a Tablet; Compilation on ‘The Bible: Extracts on the Old and New Testaments’, prepared by the Research Department of the Universal House of Justice)